Modeling of Freeway Ramp Merging Process Observed During Traffic Congestion

2004

Comp-aided Civil Eng

Self Cite

Freeway ramp merging was studied under congested traffic conditions using a driving simulator (DS). First, the results of extensive macroscopic and microscopic studies were used to establish a model for the behavior of merging drivers. Based on this behavioral model, the Freeway Merging Capacity Simulation Program (FMCSP) was developed to simulate the actual traffic conditions. This model evaluates the capacity of a merging section for a given geometric design and flow condition. Next, a DS was developed to be used in conjunction with the FMCSP. The DS and simulation were combined by replacing one vehicle in the FMCSP by the DS. A pilot study was then undertaken to test for deficiencies in the combined system. Finally, the main DS experiment was performed using 12 male drivers. Driving behavior data were collected while each participant drove in the DS through the Ichinohashi merging section. In addition, two participants of the DS experiments drove an instrumented car through the real Ichinohashi merging section. The driving behavior data from the DS, instrumented car, and observation of drivers were compared to investigate the behavior of DS driver and examine differences between the behavior of drivers using simulators and those in the real world. The results indicated that the FMCSP is capable of simulating the actual traffic conditions of congested freeway ramp merging processes, and that the insertion into a simulation of a vehicle controlled by a DS is a promising tool for the study of complicated ramp merging phenomena.

Section: And Avishai Cedermentioning

confidence: 99%

Freeway Ramp Merging Phenomena in Congested Traffic Using Simulation Combined with a Driving Simulator

2004

Comp-aided Civil Eng

Self Cite

“…Based on Figure 6, it could be concluded that drivers start switching their behavior (e.g. car-following) from free flow mode to congested flow mode when they are caught in the queue, and complete the switching when their time in the queue reaches around 15 minutes (comprehensive car-following study is carried out but it lies beyond the scope of present work however, is the subject of other studies summarized in Sarvi et. al.…”

Section: Congestion Forming and Developmentmentioning

confidence: 96%

“…The second decision, which involves the ramp driver searching for and accepting a suitable gap, has been extensively studied for the free-flow merging condition , Daganzo 1981, Makigami et al 1988, Chang and Kao 1991, Ahmed et al 1996, Kita 1999, Kurian 2000. The gap searching and acceptance maneuvers commonly observed under free-flow conditions do not occur under heavy traffic flow conditions, according to a macroscopic study by Sarvi and Kuwahara (1999) and Sarvi (2000). These macroscopic studies found no significant correlation between the acceleration lane length and the maximum flow rate in the merging sections.…”

Section: The Decision Process Of Driversmentioning

confidence: 98%

“…The tasks and decision-making processes required for drivers approaching a freeway merging point differ between free-flow conditions and congested-flow conditions. A comprehensive traffic survey and onsite observation have shown that the decision-making process of drivers in merging situations can be divided into three zones, as shown in Figure 3 (Sarvi 2000). The decisions required in each zone can be expressed as follows.…”

Section: The Decision Process Of Driversmentioning

confidence: 99%

“…The third driver decision is related to the known car-following behavior, which describes how a pair of vehicles interacts with each other, and will not be dealt with in this paper. The reader can refer to Sarvi et al 2002Sarvi et al , 2004Sarvi et al , and 2005. Table 2 lists the possible interactions between vehicles approaching and engaging the merging area under congested traffic conditions, established through thorough observations as described in section 3.…”

Section: The Decision Process Of Driversmentioning

confidence: 99%

See 2 more Smart Citations

Observing freeway ramp merging phenomena in congested traffic

J of Advced Transportation

2007

Self Cite

This work conducts a comprehensive investigation of traffic behavior and characteristics during freeway ramp merging under congested traffic conditions. On the Tokyo Metropolitan Expressway, traffic congestion frequently occurs at merging bottleneck sections, especially during heavy traffic demand. The Tokyo Metropolitan Expressway public corporation, generally applies different empirical strategies to increase the flow rate and decrease the accident rate at the merging sections. However, these strategies do not rely either on any behavioral characteristics of the merging traffic or on the geometric design of the merging segments. There have been only a few research publications concerned with traffic behavior and characteristics in these situations. Therefore, a three-year study is undertaken to investigate traffic behavior and characteristics during the merging process under congested situations. Extensive traffic data capturing a wide range of traffic and geometric information were collected using detectors, videotaping, and surveys at eight interchanges in Tokyo Metropolitan Expressway. Maximum discharged flow rate from the head of the queue at merging sections in conjunction with traffic and geometric characteristics were analyzed. In addition, lane changing maneuver with respect to the freeway and ramp traffic behaviors were examined. It is believed that this study provides a thorough understanding of the freeway ramp merging dynamics. In addition, it forms a comprehensive database for the development and M. Sarvi, M. Kuwahara and A. Ceder 146 implementation of congestion management techniques at merging sections utilizing Intelligent Transportation System.

Developing control strategies for freeway merging points under congested traffic situations using modeling and a simulation approach

J of Advced Transportation

2003

Self Cite

This work focuses on developing a variety of strategies for alleviating congestion at freeway merging points as well as improving the safety of these points. On the Tokyo Metropolitan Expressway, traffic congestion frequently occurs at merging bottleneck sections, especially during heavy traffic demand. The Tokyo Metropolitan Expressway public corporation, generally applies different empirical strategies to increase the flow rate and decrease the accident rate at the merging sections. However, these strategies do not rely either on any behavioral characteristic of the merging traffic or on the geometric design of the merging segments. There have been only a few research publications concerned with traffic behavior and characteristics in these situations. Therefore, a three-year extensive study has been undertaken to investigate traffc behavior and characteristics during the merging process under congested situations in order to design safer and less congested merging points as well as to apply more efficient control at these bottleneck sections.Two groups of strategies were investigated in this study. The First group was related to the traffic characteristics, and the second group to the geometric characteristics. In the first group, the control strategies related to closure of freeway and ramp lanes as well as lane-changing maneuver restriction were investigated through a simulation program, detector data, and field experiment. In the second group, the angle of convergence of the ramp with the freeway in relation to merging capacity was analyzed using a simulation program. Results suggested the potential benefits of using proposed strategies developed in this work and can serve as initial guidance for the reduction of delay and improvement of safety under congested traffic conditions. Majid Sarvi, is in the